The successful placement of the dental implants has been well known for many years, however, the success of the dental implants has been limited by the quality and quantity of existing bone a given patient would present with. As it is known, due to the destructive nature of dentures to the underlying jaw bone as well as to the fact that bone that is not internally stimulated by tooth roots will atrophy, the amount of bone in many people is very limited for the placement of dental implants. For example, individual tooth implants have been successfully carried out, and this procedure is now relatively common. However, this process may not be suitable for many dental patients due to a lack of available bone.
Also, as it is known, bone grafting has become an essential element for the successful treatment of those who do not have enough bone for dental implants. There are known methods, when blocks of hip bone have been affixed to the jaw, and freeze-dried demineralized bone protein has been used as a stimulant to cause the patient's bone cells to become active and lay down new bone onto the existing bone areas and into the new bone graft areas. Through the known experience and research, it has become evident that, for bone grafting to be successful, it must be given an isolated space to grow, protected from muscular pressure, tissue impingement and chewing forces. In order to create this space, many approaches have been proposed.
There has been developed an advanced dental technique which may permit those patients who have insufficient bone structure to reliably receive and hold support posts to still enjoy the benefit of detachable dentures or a fixed coupled to such support posts or artificial tooth. This known technique, which is presently outside the mainstream of dentistry, employs a maxillary and/or mandibular framework emplaced sub-periosteal, but resting on the existing bone structure with the denture support posts depending from a bar carried at the apex of each framework. Implants of this type have had good success, particularly when made in the mandibular position, but are subject to important objections, particularly as used in the maxillary position because of inter alia.
One known reason for the limited acceptance of sub-periosteal implants is the broad perception that the implant has a high degree of framework strut exposure which is a result of a lack of bone attachment to and around the struts as well as unsatisfactory soft tissue healing. As a result, the implants, particularly in the maxillary position, are sometimes subject to infection.
For example, the U.S. Pat. No. 6,030,218 describes a sub-periosteally implantable prosthesis support structure for a fixed or detachable dental prosthesis includes a framework fitted to and generally conforming to the inner and outer contours of the bony ridge structures of a person. The framework is configured to provide a space extending generally normal to the bony ridge structure to an apex to provide space for subsequent bone growth. A plurality of denture support posts are distributed about the framework and depend outwardly from the apex in substantial alignment with the bony ridge structure. During the fabrication of the prosthesis support structure, a biocompatible fine mesh screen is fixed to and spans, tent-like, the framework to substantially overlay the bone structure and the space provided for subsequent bone growth. After the support structure has been implanted, the growth of bone into the space and around the support structure is promoted to osseo-integrate the support structure with the person's bony ridge, thus providing a secure foundation for a denture or fixed dental prosthesis configured for detachable or fixed coupling with the denture support posts.
The sub-periosteally implantable dental prosthesis support structure for a fixed or detachable dental prosthesis which includes a framework fitted to and generally conforming to the inner and outer contours of the maxillary (and/or mandibular) bony ridge structures of a person.
Specifically, the prosthesis support has been surgically placed against and overlaying the patients maxillary bony ridge and beneath the adjacent soft tissue (e.g., gum tissue). The gum tissue is separated from the bony ridge by at least the thickness of the struts making up the framework, a condition which has been found conducive to the encouragement of subsequent bone growth.
The device includes the screen which overlays and is fixed to the framework with the support posts depending downwardly from the framework. The screen is fabricated from any bio-compatible material suitable as to strength and appropriate for permanent retention in the mouth of an individual. The purpose of the screen is to create a tenting of the gum tissue above the bone in order that bone will grow between and to the frame and into the weave. In addition, it serves to provide a rigid, bio-compatible structure for the gum tissue to become attached in its new, tented position.
The framework is covered with a mesh screen to effect a complete prosthesis support structure for use in the mandibular position. The screen, may be fabricated from any material suitable as to strength and appropriate for permanent retention in the mouth of an individual, and the presently preferred material is titanium, the alternative materials having been discussed above. The framework is made of a suitable material, such as titanium stock, for lightness and strength as well as appropriateness for permanent emplacement in a patient's mouth. Similarly, the mesh may be attached to the framework by any suitable means such as with an adhesive or by welding, spot welding being particularly suitable when the presently preferred material, titanium, is used, or by sintering or even by the use of suitably placed ligatures.
The mesh should be sufficiently open as to permit nutrients to readily pass to the underlying tissue, but strong enough to establish a relatively rigid structure in use. It has been found that, when titanium mesh is employed, on the order of 0.003 inch wire in about a 50.times.50 wires per inch weave is a very suitable mesh for the intended purpose. The titanium stock from which the frameworks are fabricated can be on the order of 0.050-0.200 inch thickness (the presently preferred method of fabricating the frame is as a one-piece casting).
Such principles, used for dental implant installation, are not reliably efficient and create an external extended ridge providing complexity of leveling of the original teeth with the artificial (implanted) tooth. Also, such method requires the separation of gum.
The same deficiencies inherent in the Patent Application Publication No. US2001/0012607 describes a method of growing additional maxillary (or mandibular) bone in areas of atrophy and by the use of a related device to accomplish the task. A pliable guided-tissue regeneration plate, which holds it shape after being bent, is employed as a mating component to a support screw or a dental implant and is secured to the jaw structure by fixation of the guided-tissue regeneration plate at a predetermined distance above or away from the surface of the bone to the support screw or dental implant in order to create a supported and protected space between the underside of the gum tissue and the original bone which is free from muscular and chewing pressure in order to promote bone growth.
The guided-tissue regeneration plate support and fixation system can be mated with a support screw or screws which are tenting screws designed to be mated with and then become intimately a part of the guided-tissue regeneration plate in order to grow bone in the space created by the guided-tissue regeneration plate system prior to implant placement. Additionally, the guided-tissue regeneration plate system can be utilized during implant placement by creating space adjacent to a dehisced implant by fixation of the guided-tissue regeneration plate directly to the implant in order to grow bone height or width. A guided-tissue regeneration plate according to the present invention can also be used by affixing it to an existing dental implant that has been previously placed and has undergone bone loss in order to regenerate new bone. The guided-tissue regeneration plate support and fixation system is adapted to be surgically removed after the bone has grown under its surface at a later uncovering or implant placement surgery. In an alternative preferred embodiment which provides particularly successful results and which results in faster and better bone regeneration and periosteum growth, the guided-tissue regeneration plate consists of first and second integrated components including a first support plate component having a peripheral region and a generally open central portion and a fine mesh screen juxtaposed over the central portion and fixed to the peripheral region thereof. In a functionally equivalent variant of the alternative preferred embodiment, the guided-tissue regeneration plate is fabricated starting with an imperforate plate (for example, of titanium) and then reducing the thickness of predetermined central regions of the plate, a step which can be carried out, for example, by employing a conventional photoresist mask over the plate in conjunction with an acid etch. After the desired thickness of the central regions has been obtained, the central regions may be perforated with finely spaced apertures using, for example, conventional laser machining techniques.
Specifically, the invention uses guided-tissue regeneration plate which has been molded, then bone graft material is packed beneath the plate and against the existing bony ridge. After a period of approximately four-to-eight months, a new bony ridge will form within the space created by the guided-tissue regeneration plate support, its fixation system, and the cortical bone (more precisely, the gum tissue). In order to place a guided-tissue regeneration plate support and fixation system according to the present invention, the tissue is first reflected away from the bony ridge to expose the ridge in its entirety. The palatal gum tissue is reflected, the facial gum tissue is reflected, and a guided-tissue regeneration plate support screw is placed into the bony ridge. Later the guided-tissue regeneration plate support and fixation system has been removed exposing the new bony ridge (a small hole remains after the removal of the guided-tissue regeneration plate support screw) and implant can be placed (installed) into the new bony ridge (a tooth can be attached to the implant later).
Such method may easily traumatize the tissue.
The U.S. Pat. No. 7,396,232 describes the method and device for periosteal distraction. The device by this patent uses as jack placed beneath the periosteum through a small incision. This jack lifts the Schneiderian membrane. When the periosteum reached the desired dimension the jack is taken out and a bone graft is placed as described above. For instance, FIG. 15B of the mentioned above patent shows a preferred embodiment using the final dental implant as the elevating screw (jack). The preferably tapered implant 200 with preferably round apical region and preferably threads along the body of the implant is inserted through the alveolar ridge to reach the Schneiderian membrane 146. The implant is protruding through the gums 201 to the oral cavity. Over the implant 200 a tube 202 is placed reaching the alveolar bone 147.
This method allows to avoid the necessity to stretch the mucoperiosteal tissue therefore reducing the complications: The methods to regenerate the bone are well known. The known methods use the distraction osteogenesis, which is a process whereby bone is stretched to increase bone volume. According to distraction osteogenesis processes, at least one portion of a bone is at least partially separated from the bone. The position of the portion is gradually altered with respect to the bone. Time is then provided for new bone to fill in the space between the portion and the overall bone.
When distraction osteogenesis is used in dentistry dental applications, a portion of a patient's jawbone will be at least partially severed from the overall jawbone. The jawbone segment may then be gradually separated from the rest of the jawbone. New bone then fills in the space between the segment and the jawbone. By increasing the volume of bone in the jawbone, additional area can be provided to anchor or at least more securely anchor dental implants. Distraction osteogenesis can also be used in dental applications simply to strengthen a location on the jawbone to increase the bone volume at that location even if implants are not to be secured in the jawbone at that location.
These techniques of distraction osteogenesis has the known disadvantage, i.e., this procedure can be done if the height of the ridge is at least 6 mm.
The U.S. Pat. No. 7,396,232 allows the distraction osteogenesis without cutting a segment of the bone therefore the procedure is simple minimal invasive and not traumatic. In this invention the Schneiderian membrane is separated from the bone by the jack (by the dental implant as the elevating screw).
This method uses the tooth cannel to elevate the Schneiderian membrane. The another very important deficiency of this method is the use of the mechanical jack (the dental implant as the elevating screw (jack)). The Schneiderian membrane is a very sensitive and thin membrane for mechanical instruments, even such as screw. Additionally, the most dental implants (specifically screw-type dental implants) have the very sharp (screw-type) free end of the implant, which can easily traumatize and even injury the Schneiderian membrane.
Therefore, the mentioned known methods and devices have the described above deficiencies which are eliminated in the improved device for dental implant installation.
While the mentioned above prior art fulfill their respective, particular objectives and requirements, the mentioned inventions do not disclose, teach and/or suggest the device for dental implant installation including the elements (components/parts) inflating its/their capacity/volume to securely move the Schneiderian membrane providing internal place for the material grafting the artificial bone(s).
Those skilled in the art will readily observe that numerous modifications and advantages of the improved device for dental implant installation may be made while retaining the teachings of the invention.
Thus, the known prior art do not provide the efficient, satisfied, convenient (without gum separation) device for dental implant installation according to the present invention substantially departs from the devices of the prior art.